<!-- 参考文章 https://segmentfault.com/a/1190000013301463 -->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>
  /* 圣杯 */
  <style>
    * {
        padding: 0;
        margin: 0;
    }
    body {
        min-width: 600px;
    }
    header,
    footer {
        text-align: center;
        width: 100%;
        background-color: #bbbbbb;
    }
    .text {
        text-align: center;
        line-height: 200px;
        font-size: 40px;
    }

    .bd {
        overflow: hidden; /* 清除浮动 */
        padding: 0 200px 0 200px;
    }

    .main {
        float: left;
        width: 100%;
        height: 200px;
        background-color: #ddd;
    }
    .left {
        opacity: 0.5;
        float: left;
        width: 200px;
        height: 200px;
        background-color: #da4242;
        /* 产生布局效果的属性 */
        margin-left: -100%;
        position: relative;
        left: -200px;
    }
    .right {
        /* opacity: 0.5; */
        float: left;
        width: 200px;
        height: 200px;
        background-color: #4ddef1;
        /* 产生布局效果的属性 */
        margin-left: -200px;
        position: relative;
        left: 200px;
    }

  </style>
  <header>圣杯布局</header>
  <div class="bd">
    <div class="main text">
      main
    </div>
    <div class="left text">
      left
    </div>
    <div class="right text">
      right
    </div>
  </div>
  <footer>footer</footer>
</body>
</html>

<!-- <!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>双飞翼布局</title>
  <style>
    * {
      padding: 0;
      margin: 0;
    }

    header,
    footer {
      text-align: center;
      width: 100%;
      background-color: #bbbbbb;
    }

    .text {
      text-align: center;
      line-height: 200px;
      font-size: 40px;
      color: #fff;
    }

    .bd {
      overflow: hidden;
    }

    .main {
      float: left;
      width: 100%;
      height: 200px;
      background-color: #ddd;
    }

    .main-content {
      margin: 0 200px;
    }

    .left {
      float: left;
      width: 200px;
      height: 200px;
      background-color: #da4242;
      /* 产生布局效果的属性 */
      margin-left: -100%;
    }

    .right {
      float: left;
      width: 200px;
      height: 200px;
      background-color: #4ddef1;
      /* 产生布局效果的属性 */
      margin-left: -200px;
    }
  </style>
</head>

<body>
  <header>双飞翼布局</header>
  <div class="bd">
    <div class="main text">
      <div class="main-content">main</div>
    </div>
    <div class="left text">
      left
    </div>
    <div class="right text">
      right
    </div>
  </div>
  <footer>footer</footer>
</body>

</html> -->